A multiple-input multiple-output (MIMO) technology allows using a plurality of transmit antennas and a plurality of receive antennas at a transmit end and a receive end, respectively, so as to send and receive signals by using the plurality of antennas at the transmit end and the receive end, respectively. The MIMO technology is mainly used to improve a capacity and reliability of a channel.
Different MIMO transmission modes (TM) are defined for a Long Term Evolution (LTE) system. A base station informs, by using radio resource control (RRC) signaling, a terminal of a transmission mode used for a current physical downlink shared channel (PDSCH) and a related configuration parameter, and the terminal performs corresponding signal processing and reception. At present, a total of 10 TMs, TM1 to TM10, are defined for the LTE system. The MIMO technology is mainly classified into a spatial multiplexing technology and a space diversity technology. Spatial multiplexing is further classified into open-loop spatial multiplexing and closed-loop spatial multiplexing. A main difference between closed-loop spatial multiplexing and open-loop spatial multiplexing lies in that a terminal needs to feed back precoding matrix indicator (PMI) information in closed-loop spatial multiplexing. Closed-loop spatial multiplexing is used in TM4, TM6, TM8, TM9 and TM10, and open-loop spatial multiplexing is used in TM3. When closed-loop spatial multiplexing is used for data transmission, an incorrect PMI may be reported, causing a series of problems such as an increase in a residual block error rate and an increase in a packet loss rate. As a result, network performance is reduced.